Is 82 a prime number?
82 is not a prime number. Here is the quickest way to see it.
The answer
No. 82 is not a prime number: 2 × 41 = 82.
How to see that 82 is not prime
82 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 82.
82 has four factors: 1 and 82, plus one pair in between, 2 and 41.
Split 82 into prime factors
82 splits straight into two primes, 2 × 41, so its factor tree has only one branch.
82 in the times tables
No fact from the 2 to 12 times tables, up to × 12, makes 82. Its smallest pair, 2 × 41, needs the 41 times table, which goes past 12.
Quick checks that catch 82
- The last digit, 2, is even, so 2 goes in.
82 at a glance
- In words
- eighty-two
- In Roman numerals
- LXXXII
- Odd or even
- Even: it ends in 2
- Its factors add up to
- 126, or 44 without 82 itself, which makes 82 a deficient number
The numbers either side of 82
- 81 is not prime. Its digits add up to 8 + 1 = 9, which is a multiple of 3. That means 81 is a multiple of 3 too, so 3 is a factor. Check 81 in full
- 83 is prime: 2, 3, 5 and 7 do not go into it, and 11 × 11 is already past 83. Check 83 in full
Turn the digits round
82 backwards is 28. 28 is not prime. 28 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 28. Check 28 in full
Related pages
More numbers
Questions parents ask
Which prime numbers are either side of 82?
79 below it and 83 above it, a gap of 4.
What is 82 squared?
82 × 82 = 6724.
What is the smallest number with as many factors as 82?
6. It has 4 factors, the same as 82.
Number facts are the base of 11+ maths
Factors, multiples, primes and square numbers come up all over 11+ maths, from simplifying fractions to ratio. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.